Saibal Mitra: > ... a so-called mirror world could exist. Nature would then be > symmetric under parity. Their so-called exact parity model predicts > the existence of so-called ''mirror matter''. Each particle is > postulated to have a mirror partner with similar properties (they > behave exactly as the mirror image of there partners, e.g. mirror > neutrino's would be right-handed). This is thus similar to > anti-mater, the main difference is that mirror particles and > ordinary particles only have very weak interactions ... Now that would be neat. Too bad some authors have used "mirror matter" as a synonym for antimatter. Well, if it turns out to be real we might still call it dark matter, though that usage will also have to be sharpened. Something that has bothered me regarding WIMP dark matter in general, shouldn't there be a lot of it at the bottom of familiar gravity wells like the sun and the earth, and wouldn't that hugely confuse the conventional matter models that most everyone uses to deduce, for instance, the composition of the earth's core or the sun and its fusion processes? Dark matter that has fallen to earth (and into the sun) and expended its energy on impact would accumulate, probably deep down, no?